Wormsign is tell-tale signals that a sandworm was approaching during spice mining on the planet Arrakis. It usually manifested itself as static charges on the surface of sand dunes. Also when the worm reaches a shallow depth, there is a sign of a bulge or surge in the sands.
The observation of wormsign usually meant that a sandworm's estimated time of arrival could be calculated.
- In the comedy series Mystery Science Theater 3000, the phrase is parodied to “movie sign.”